INCISTEROLS, A NEW CLASS OF HIGHLY DEGRADED STEROLS FROM THE MARINE SPONGE DICTYONELLA-INCISA

Four new sterols (1-4) with an unprecedented highly degraded skeleton were isolated from the Mediterranean sponge Dictyonella incisa. The structures of these new compounds were assigned on the basis of spectral studies, particularly NMR and mass spectrometry. A plausible pathway for the biogenesis of these compounds starting from cholestatrien-3β-ols through a unique in vivo oxidative process is proposed. The entire sterol content of the sponge and the structural elucidation of two new polyhydroxy sterols (6b and 6d) are also reported. © 1990, American Chemical Society. All rights reserved.